Thingmagic M5e-Compact Manual de usuario descargar pdf (Pagina 49)

Serial Port

Functionality of the Embedded Modules 49

Serial Port

The modules communicate to a host processor via the TTL logic level UART serial port,

accessed on the 12-pin digital connector for M5e/M5e-Compact. See M5e/M5e-Compact

Digital Connectors.

UART TTL Level TX

V-Low: Max 0.4 VDC

V-High: 2.9 to 3.3 VDC

8 mA max

UART TTL Level RX

V-Low: -0.3 to 0.8 VDC

V-High: 2 to 5.5 VDC

(Tied to 3.3 V through a pull-up resistor. Not harmful, but not recommended to drive

the input above 3.3 V because then the input will be sourcing current to the 3.3 V

supply.)

A level converter could be necessary to interface to other devices that use standard 12V

RS-232. Only three pins are required for serial communication (TX, RX, and GND).

Hardware handshaking is not supported. The serial port has an interrupt-driven FIFO that

empties into a circular buffer.

The developer is responsible for ensuring that the host processor’s receiver has the

capability to receive up to 256 bytes of data at a time without overflowing.

General Purpose Inputs/Outputs (GPIO)

The Mercury Embedded modules have four TTL level signals, two input lines and two

output lines, available on the 12-pin (M5e/M5e-Compact) digital connector. These can be

controlled via the Get User GPIO Inputs and Set User GPIO Outputs commands.

Note

If you are Using a Multiplexer the available GPIO Outputs will be reduced to 1

or 0 depending on whether one or both are used as control lines as specified

by Set Reader Configuration(9Ah).

For further information, see Get User GPIO Inputs (66h) and Set User GPIO Outputs (96h).

1 2 ... 44 45 46 47 48 49 50 51 52 53 54 ... 251 252

Sin comentarios

Thingmagic M5e-Compact Manual de usuario Pagina 49